Apparatus for Testing Thermal Insulation Properties

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When you are camping out overnight and everything is getting cold, you don't want to spend the night shivering. You need gear with insulation - both on top of you and underneath you. For that matter, the same applies during the daytime when in the snow. But just how good that gear is at insulating you from the cold depends on what sort of thermal insulator it is, and that involves a measurement called the 'R-Value'. The letter 'R' stands (most likely) for resistance - as in resistance to the flow of heat.

Now many manufacturers give some sort of rating for their insulating gear, but unfortunately some of those claims are believed to be a trifle exaggerated, while some others are just unbelievable. It is routine, in a BPL review, for the writer to actually measure things like length, width, weight and so on, rather than rely entirely on the claimed values. With this data we can see who is stretching the truth. We decided that BPL should also have the facility to measure R-Values. This article describes how a measurement system for R-value works and how one was built. This system will be featured in subsequent surveys and reviews. A survey of summer and winter airmats will likely be the first to feature this.